code: def setUpClass(cls):
      cls.data = sample_data
      cls.data.columns = cls.data.columns.str.lower()
      cls.open = cls.data["open"]
      cls.high = cls.data["high"]
      cls.low = cls.data["low"]
      cls.close = cls.data["close"]
      if "volume" in cls.data.columns:
          cls.volume = cls.data["volume"]
  
imports: from .config import error_analysis, sample_data, CORRELATION, CORRELATION_THRESHOLD, VERBOSE
  from .context import pandas_ta
  from unittest import TestCase, skip
  import pandas.testing
  from pandas import DataFrame, Series
  import talib
label_desc: Use image node_id 1 for calling the TestTrend obj's underlying member method code with example usage: obj.setUpClass(cls) without return types